# Who says you don't need a computer?

Euler's Phi function is a function $$\phi : \mathbb{N} \rightarrow \mathbb{N}$$ which when applied to a natural number $$n$$, gives the number of natural numbers less than or equal to $$n$$ that are coprime to $$n$$.

Find $$\displaystyle \sum_{n=1}^{1000} \phi(n)$$

Suggestions:-

• Solve this with a program in language you like, rather than using a calculator (Programming practice) ..... Make use of the properties of the Phi function.

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